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SWRS224A – FEBRUARY 2019 – REVISED AUGUST 2019
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Detailed Description
Copyright © 2019, Texas Instruments Incorporated
6.10 Restoring Factory Default Configuration
The module has an internal recovery mechanism that rolls back the file system to its predefined factory
image or restoring the factory default parameters of the device. The factory image is kept in a separate
sector on the sFLASH in a secure manner and cannot be accessed from the host processor. The following
restore modes are supported:
•
None—no factory restore settings
•
Enable restore of factory default parameters
•
Enable restore of factory image and factory default parameters
The restore process is performed by calling software APIs, or by pulling or forcing SOP[2:0] = 011 pins
and toggling the nRESET pin from low to high.
The process is fail-safe and resumes operation if a power failure occurs before the restore is finished. The
restore process typically takes about 8 seconds, depending on the attributes of the serial Flash vendor.
6.11 Boot Modes
6.11.1 Boot Mode List
The CC3235MODx MCU implements a sense-on-power (SoP) scheme to determine the device operation
mode.
SoP values are sensed from the module pin during power up. This encoding determines the boot flow.
Before the device is taken out of reset, the SoP values are copied to a register and used to determine the
device operation mode while powering up. These values determine the boot flow as well as the default
mapping for some of the pins (JTAG, SWD, UART0).
lists the pull configurations.
All CC3235MODx MCUs contain internal pull down resistors on the SOP[2:0] lines. The application can
use SOP2 for other functions after chip has powered up. However, to avoid spurious SOP values from
being sensed at power up, TI strongly recommends using the SOP2 pin only for output signals. The SOP0
and SOP1 pins are multiplexed with the WLAN analog test pins and are not available for other functions.
Table 6-5. CC3235MODx Functional Configurations
NAME
SOP[2]
SOP[1]
SOP[0]
SoP MODE
COMMENT
UARTLOAD
Pullup
Pulldown
Pulldown
LDfrUART
Factory, lab Flash, and SRAM loads
through the UART. The device waits
indefinitely for the UART to load code.
The SOP bits then must be toggled to
configure the device in functional mode.
Also puts JTAG in 4-wire mode.
FUNCTIONAL_2WJ
Pulldown
Pulldown
Pullup
Fn2WJ
Functional development mode. In this
mode, 2-pin SWD is available to the
developer. TMS and TCK are available
for debugger connection.
FUNCTIONAL_4WJ
Pulldown
Pulldown
Pulldown
Fn4WJ
Functional development mode. In this
mode, 4-pin JTAG is available to the
developer. TDI, TMS, TCK, and TDO are
available for debugger connection. The
default configuration for CC3235MODx
MCUs.
UARTLOAD_FUNCTIONAL_4WJ
Pulldown
Pullup
Pulldown
LDfrUART_FnWJ
Supports Flash and SRAM load through
UART and functional mode. The MCU
bootloader tries to detect a UART break
on UART receive line. If the break signal
is present, the device enters the
UARTLOAD mode, otherwise, the device
enters the functional mode. TDI, TMS,
TCK, and TDO are available for
debugger connection.